diuretics (loop)

Contraindicated in:

Hypersensitivity;
Cross-sensitivity with thiazides and sulfonamides may occur;
Hepatic coma;
Anuria;
Hepatic cirrhosis (SUBQ only);
Some liquid furosemide products may contain alcohol and should be avoided in patients with known intolerance.

Use Cautiously in:

Severe hepatic impairment (may precipitate hepatic coma; concurrent use with potassium-sparing diuretics may be necessary);
Electrolyte depletion;
Diabetes;
Hypoproteinemia or severe renal impairment (↑ risk of ototoxicity);
OB: Safety and effectiveness of torsemide not established in children; bumetanide is a potent displacer of bilirubin and should be used cautiously in critically ill or jaundiced neonates due to risk of kernicterus;
Geri: Older adults may have ↑ risk of side effects, especially hypotension and electrolyte imbalance.

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypotension

Derm: ERYTHEMA MULTIFORME (EM), photosensitivity, pruritus, rash, STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS, urticaria

EENT: hearing loss, tinnitus

Endo: hyperglycemia

F and E: dehydration, hypochloremia, hypokalemia, hypomagnesemia, hyponatremia, hypovolemia, metabolic alkalosis

GI: ↑liver enzymes (furosemide), constipation, diarrhea, dry mouth, dyspepsia, nausea, vomiting

GU: acute renal failure, renal impairment, excessive urination

Hemat: blood dyscrasias (furosemide)

Metab: hypercholesterolemia, hypertriglyceridemia, hyperuricemia

MS: arthralgia (torsemide), muscle cramps, myalgia (torsemide)

Neuro: dizziness, encephalopathy (bumetanide and furosemide), headache, insomnia(torsemide), nervousness (torsemide)

Interactions ⬆ ⬇

Drug-drug:

↑risk of hypotension with antihypertensives, nitrates, or acute ingestion of alcohol.
↑risk of hypokalemia with other diuretics, piperacillin/tazobactam, amphotericin B, stimulant laxatives, and corticosteroids.
Hypokalemia may ↑ risk of digoxin toxicity.
May ↑ levels and risk of toxicity of lithium.
↑risk of ototoxicity with aminoglycosides or cisplatin.
↑risk of nephrotoxicity with other nephrotoxic drugs, including aminoglycosides, cisplatin, NSAIDs, ACE inhibitors, angiotensin II receptor blockers, and radiocontrast agents.
May ↑ levels and risk of toxicity of methotrexate.
Cyclosporine may ↑ risk of gouty arthritis.
May ↑ risk of bleeding with warfarin, thrombolytic agents, or anticoagulants.
CYP2C9 inhibitors, including amiodarone, fluconazole, miconazole, and oxandrolone, may ↑ levels and risk of toxicity of torsemide.
CYP2C9 inducers, including rifampin, may ↓ levels and effectiveness of torsemide.
Torsemide may ↑ levels and risk of toxicity of CYP2C9 substrates, including celecoxib, phenytoin, or warfarin.

Availability ⬆ ⬇

Bumetanide

(Generic available)

Tablets: 0.5 mg; 1 mg; 2 mg; 5 mg
Solution for injection: 0.25 mg/mL

Furosemide

(Generic available)

Tablets: 20 mg; 40 mg; 80 mg, ; 500 mg
Oral solution 10 mg/mL: orange flavor, 8 mg/mL: pineapple-peach flavor: 8 mg/mL; 10 mg/mL
Solution for intravenous/intramuscular injection: 10 mg/mL
Solution for SUBQ injection (Furoscix) (prefilled cartridges): 80 mg/10 mL

Torsemide

(Generic available)

Tablets: 5 mg; 10 mg; 20 mg; 40 mg; 60 mg; 100 mg

Route/Dosage ⬆ ⬇

Bumetanide

PO (Adults ): 0.5–2 mg/day as a single dose. Up to 2 additional doses may be given during the day every 4–5 hr (up to 10 mg/day). Alternate-day or every-2–3-day regimens may also be used.
IM IV (Adults ): 0.5–1 mg; may be repeated every 2–3 hr as needed (up to 10 mg/day).

Furosemide

PO (Adults ): Edema: 20–80 mg/day as a single dose initially; may repeat in 6–8 hr; may ↑ dose by 20–40 mg every 6–8 hr until desired response. Maintenance doses may be given once or twice daily or intermittently for 2–4 days/wk (doses up to 2.5 g/day have been used in patients with HF or renal disease). Hypertension: 40 mg twice daily initially (when added to regimen, ↓ dose of other antihypertensives by 50%); adjust further dosing based on response; Hypercalcemia: 120 mg/day in 1–3 doses.
PO (Children ): 2 mg/kg as a single dose; may ↑ by 1–2 mg/kg every 6–8 hr (1–2 mg/kg/day initially, up to 5–6 mg/kg/day). Longer dosage intervals are recommended in neonates.
IM IV (Adults ): Edema: 20–40 mg; may repeat in 2 hr and ↑ by 20 mg every 2 hr until response is obtained; maintenance dose may be given once or twice daily; Acute pulmonary edema: 40 mg; after 1 hr may give additional 80 mg (in HF and renal failure, daily doses of up to 2.5 g have been used); Hypercalcemia: 80–120 mg; may repeat every 1–4 hr; titrate by response.
IM IV (Children ): 1 mg/kg; may ↑ by 1 mg/kg every 2 hr (not to exceed 6 mg/kg).
IM IV (Neonates ): 1–2 mg/kg/dose every 12–24 hr.
SUBQ (Adults ): 30 mg over the 1st hr, then 12.5 mg per hr over the next 4 hr with the single-use on-body infusor. Replace with oral diuretic therapy as soon as possible.

Torsemide

PO (Adults ): HF: Generic or Sooanz: 20 mg once daily; may double dose until desired effect obtained (max = 200 mg/day). Chronic renal failure: Generic or Soaanz: 20 mg once daily; may double dose until desired effect obtained (max = 200 mg/day). Hepatic cirrhosis: Generic only: 5–10 mg once daily (with aldosterone antagonist or potassium-sparing diuretic); may double dose until desired effect obtained (max = 40 mg/day). Hypertension: 5 mg once daily; may ↑ to 10 mg once daily after 4–6 wk (if still not effective, add another agent).

US Brand Names ⬆ ⬇

bumetanide: Bumex,

furosemide: Furoscix, Lasix,

torsemide: ~~Demadex,~~ Soaanz

Action ⬆ ⬇

Inhibit the reabsorption of sodium and chloride from the loop of Henle and distal renal tubule.
Increase renal excretion of water, sodium, chloride, magnesium, hydrogen, and calcium.
May have renal and peripheral vasodilatory effects.
Effectiveness persists in impaired renal function.

Therapeutic effects:

Diuresis and subsequent mobilization of excess fluid (edema, pleural effusions).
Decreased BP.

Classifications ⬆ ⬇

Therapeutic Classification: diuretics

Pharmacologic Classification: loop diuretics

Pharmacokinetics ⬆ ⬇

Absorption: Bumetanide: well absorbed after oral or IM administration. Furosemide: 60–75% absorbed following oral administration; also absorbed from IM sites; IV administration results in complete availability; 99.6% absorbed after SUBQ administration. Torsemide: 80% absorbed following oral administration.

Distribution: Bumetanide and Torsemide: well distributed to tissues.

Protein Binding: All are >91%.

Metabolism/Excretion: Bumetanide: Partially metabolized by the liver; 50% eliminated unchanged by the kidneys; 20% excreted in feces. Furosemide: Some metabolism by liver (30–40%), some nonhepatic metabolism, and some renal excretion as unchanged drug. Torsemide: Primarily metabolized by CYP2C9, with minor metabolism via CYP2C8 and CYP2C18. 80% metabolized by liver; 20% excreted in urine.

Half-Life: Bumetanide: 60–90 min (6–15 hr in neonates); Furosemide: 30–120 min (↑ in renal impairment and neonates, markedly ↑ in hepatic impairment); Torsemide: 210 min.

Canadian Brand Names ⬆ ⬇

bumetanide: Burinex,

furosemide: Lasix Special

Time/Action Profile ⬆ ⬇

( diuretic effect)

ROUTE	ONSET	PEAK	DURATION
Bumetanide–PO	30–60 min	1–2 hr	3–6 hr
Bumetanide–IM	40 min	1–2 hr	4–6 hr
Bumetanide–IV	within min	15–45 min	3–6 hr
Furosemide–PO	30–60 min	1–2 hr	6–8 hr
Furosemide–IM	10–30 min	unknown	4–8 hr
Furosemide–IV	5 min	30 min	2 hr
Furosemide–SUBQ	unknown	unknown	8 hr
Torsemide–PO	within 60 min	60–120 min	6–8 hr

Patient/Family Teaching ⬆ ⬇

Explain purpose and side effects of loop diuretics. Instruct to take as directed. Take missed doses as soon as possible; do not double doses. Advise patient to read Patient Information before starting and with each Rx refill in case of changes.
- Emphasize the importance of routine follow-up examinations. Periodic lab tests will be needed.
- Hypertension: Advise patients on antihypertensive regimen to continue taking medication, even if feeling better. Furosemide and torsemide control but do not cure hypertension.
- Reinforce the need to continue additional therapies for hypertension (weight loss, exercise, restricted sodium intake, stress reduction, regular exercise, moderation of alcohol consumption, cessation of smoking).
- Caution patient to make position changes slowly to minimize orthostatic hypotension. Caution patient that the use of alcohol, exercise during hot weather, or standing for long periods during therapy may enhance orthostatic hypotension.
- Instruct patient to consult health care provider regarding a diet high in potassium (see Food Sources for Specific Nutrients).
- Advise patient to contact health care provider of gain >3 lb in one day.
- Instruct patient to notify health care provider of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care provider before taking any OTC medications concurrently with this therapy.
- Instruct patient to notify health care provider of medication regimen prior to treatment or surgery.
- Caution patient to use sunscreen and protective clothing to prevent photosensitivity reactions.
- Advise patient to contact health care provider immediately if rash, muscle weakness, cramps, nausea, dizziness, numbness, or tingling of extremities occurs.
- Advise patient taking furosemide tablets not to change brands when refilling prescription; bioavailability among brands is variable.
- Advise patients with diabetes to monitor blood sugar closely, because loop diuretics may cause ↑ blood sugar levels.
- Caution older patients or their caregivers about ↑ risk for falls. Suggest strategies for fall prevention.
- Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding. Loop diuretics are not recommended for use during pregnancy, except when necessary for treating pulmonary edema in HF. Monitor fetal growth during pregnancy; ↑ risk for higher birth weights.

section name header

Indications ⬇

Contraind./Precautions ⬆ ⬇

Adv. Reactions/Side Effects ⬆ ⬇

Interactions ⬆ ⬇

Availability ⬆ ⬇

Route/Dosage ⬆ ⬇

US Brand Names ⬆ ⬇

Action ⬆ ⬇

Classifications ⬆ ⬇

Pharmacokinetics ⬆ ⬇

Canadian Brand Names ⬆ ⬇

Time/Action Profile ⬆ ⬇

Patient/Family Teaching ⬆ ⬇

Pronunciation ⬆